An army led by Grand Marshal Las Heras crosses the Andes to join San Martín in the liberation of Chile from Spain.

The Army of the Andes was a military force created by the United Provinces of the Río de la Plata (Argentina) and assembled by General José de San Martín as part of his campaign to liberate Chile from the Spanish Empire. In 1817, it crossed the Andes Mountains from the Argentine province of Cuyo and succeeded in its objective by driving the Spanish out of Chile.

Grand marshal is a ceremonial, military, or political office of very high rank. The term has its origins with the word "marshal" with the first usage of the term "grand marshal" as a ceremonial title for certain religious orders. The following are some additional usages of the term grand marshal:

Grand Marshal Juan Gregorio de las Heras was an Argentine soldier who took part in the Spanish American wars of independence and was also a governor of the province of Buenos Aires.

The Crossing of the Andes was one of the most important feats in the Argentine and Chilean wars of independence. A combined army of Argentine soldiers and Chilean exiles crossed the Andes mountains, which separate Argentina from Chile, to invade Chile, leading to its liberation from Spanish rule.

José Francisco de San Martín y Matorras, nicknamed "the Liberator of Argentina, Chile and Peru", was an Argentine general and the primary leader of the southern and central parts of South America's successful struggle for independence from the Spanish Empire who served as the Protector of Peru. Born in Yapeyú, Corrientes, in modern-day Argentina, he left the Viceroyalty of the Río de la Plata at the early age of seven to study in Málaga, Spain.